Method of making die structure



June 21, 1966 F. ss ETAL 3,256,753

METHOD OF MAKING DIE STRUCTURE Filed June 22, 1962 2 Sheets-Sheet 1 EEOOOOOOOOOOOO 50 w mu INVENTORS wwwmagwg June 21, 1966 D ss ETAL 3,256,753

METHOD OF MAKING DIE STRUCTURE Filed June 22, 1962 2 Sheets-Sheet 2 is? 1 H'W Hr III llfll I! 65 n I F E 0 O Q 0 0 O 00 g 30 .1 E0 .93 J00 m d 0Z2? 5a: $41M, MC, mawmm United States Patent 3,256,753 METHOD OF MAKING DIE STRUCTURE Lester F. Dasse, St. Joseph, and Richard J. Ott, New Buffalo, Mich., assignors to Arro Plastics, Inc., Baroda, Mich., a corporation of Michigan Filed June 22, 1962, Ser. No. 204,388 Claims. (Cl. 76107) The present invention relates to a novel die structure and a method of making the same, and more particularly to a novel die set of a type having complementary male and female members and adapted for various uses including the stamping of blanks or parts-from various stock materials including sheet metal. 4

Die sets which have heretofore been constructed in accordance with generally accepted procedures have required the use of highly skilled labor and substantial expenditures of time. As a result such heretofore generally used die sets have been relatively expensive.

It is an important object of the present invention to provide a novel die set construction and a novel method for making the same whereby die sets may be produced in a relatively short time and with relatively unskilled labor and thus economically.

A more specific object of the present invention is to provide a novel die set and method of making the same of the above described type wherein steel rule blade or die elements are utilized for presenting workpiece cutting or forming edges.

A further object of the present invention is to provide a novel apparatus for facilitating the production of die structures of the above described type.

Other objects and advantages of the present invention Will become apparent from the following description and the accompanying drawings wherein:

FIG. 1 is a perspective view showing an apparatus and a die set under construction in accordance with the present invention;

FIG. 2 is a fragmentary sectional view showing a die set constructed in accordance with the present invention mounted on a punch press or similar apparatus;

FIG. 3 is an exploded perspective view showing complementary members of a die set constructed in accordance with the present invention;

FIG. 4 is an enlarged fragmentary perspective view showing a die set in an intermediate stage of construction;

FIG. 5 is a fragmentary sectional view showing a die set in an advanced stage of construction; and

FIG. 6 is an enlarged fragmentary sectional view taken generally along line 66 in FIG. 1 and showing the apparatus constructed in accordance with the present invention which may be used for producing die sets.

Referring now more specifically to the drawings wherein like parts are designated by the same numerals throughout the various figures, a die set 10 incorporating features of the present invention is shown in FIGS. 2 and 3. The set 10 comprises complementary male and female die members =12 and 14 respectively adapted to be mounted on relatively reciprocable opposed portion-s 16 and 18 of a punch press or similar apparatus. In the embodiment shown for the purpose of illustrating the present invention, the die members are particularly suitable for stamping or blanking various materials such as metals, wood, fabric, paper, and plastic.

The die member 12 comprises a body 20 of tough, strong material which is cast or poured in the manner de- 3,256,753 Patented June 21, 1966 scribed below and which is preferably a resinous thermosetting plastic material. The body 20 is enclosed by a frame 22 which is preferably formed from a magnetic material but, in certain instances, may be formed from wood or other nonmagnetic materials. In the specific embodiment shown, the frame 22 is formed from steel and includes a plurality of rectangularly arranged side frame members having end portions connected together by screws 24 and being bonded to the body 20 by the inherent adhesive characteristic of the plastic material from which the body is formed. Brackets 26 are secured to opposite end portions of the frame 22 for adapting the die member 12 to be detachably connected with the above mentioned portion '16 of the punch press or the like.

Steel rule blade or die elements 28 are embedded in and project from the body 20 for providing the workpiece shearing or processing edges of the die member 12. The steel rule elements 28 are arranged and assembled with the body 20 in accordance with the method which will be described in detail below. It will be noted that the steel rule elements extend entirely through the body 20 so that edges '30 thereof are substantially flush with a back surface 32 of the body 20 whereby the portion 16 of the punch press or the like serves to back up or support the blade elements 28. As shown best in FIG. 4, each of the blade elements 28 is formed with a bridge opening 34 therethrough through which portions of the plastic material forming the body 20 extend for connecting the areas of the body respectively located inside of and outside of the closed figure defined by the blade elements 28.

The blade elements.28 are proportioned so that they extend substantially forwardly or downwardly from a front face 35 of the body 20. Thus the steel rule blade elements 28 project for piercing and cutting workpiece stock material having any desired thickness up to the limit imposed by the amount the blade elements project from the body surface 35. It has been found that steel rule die structures of the type contemplated herein may be utilized for blanking parts from sheet metal having a substantial thickness which may, for example, be in excess of about one inch. Of course the die structure may also be used for blanking parts from relatively thin stock material. Preferably the steel rule blade elements 28 are provided with sharpened edges 36 for facilitating the cutting action.

Bushings 38 are embedded in the body 20 at spaced locations, preferably during the pouring or casting of the body. These bushings are adapted to accommodate guide rods 40 which serve to maintain the die members 12 and 14 in proper alignment. Spring biased plungers 42 or other suitable yieldable means are mounted on or embedded in the body 20 for the purpose of knocking out or disengaging a workpiece from the blade elements 28 upon the completion of a stamping operation.

The die member 14 also includes a body 44 of tough, strong pourable or c'astable material which is preferably a resinous thermosetting plastic. It is contemplated that various filler materials including fibrous and metallic materials may be mixed with the plastic for forming the body 44 as well as the above described body 20.

The body 44 is encircled by a frame structure 46 essential identical to the previously described frame 22 and preferably formed from steel or other magnetizable side frame members secured together by screws 48. Brackets 50 are connected with opposite ends of the frame structure 46 for adapting the die member 14 to be detachably connected to the portion 18 of the punch press or other apparatus. Bushings 52 are embedded in the body 44 for cooperative engagement with the guide rods 40.

The die member 14 is provided with steel rule blade or die elements 54 embedded in the body 44. Upper edges 56 of the blade elements 54 are substantially flush with an upper surface 58 of the body 44. Lower edges 60 of the blade elements 54 are substantially flush with the bottom or back surface 62 of. the body 44 so that the blade elements are directly supported by the portion 18 of the punch press or similar apparatus. The blade elements 54, like the blade elements 28 described above, are provided with bridge openings 64 so that portions of the body 44 within and without the blade elements 54 are directly joined to each other.

The blade elements 54 are arranged in a pattern substantially identical to the pattern of the blade elements 28. However the blade elements 54 are positioned in accordance with the method of the present invention which will be described in detail below so that they are slightly olfset from the blade elements 28 for providing a predetermined clearance between the blade elements 28 and 54 when the die members 12 and 14 are moved together during a workpiece blanking or forming operation. At the same time the blade elements 54 are positioned with respect to the blade elements 28 so that they closely follow not only the desired configuration of the blade elements 28 but also any deviations in the blade elements 28 from the desired configuration whereby interference between the blade elements 28 and the blade elements 54 is precluded.

As shown in FIGS. 2 and 3, one side surface of the blade elements 54 is fully engaged by and supported by the body 44. A slot 66 is formed in thebody member 44 at the opposite side of the blade elements 54, which slot has a width and depth suflicient for accommodating the projecting portion of the blade elements 28 when the die members 12 and 14 are brought together during a workpiece processing operation.

In accordance with certain features of the present invention, the die members 12 and 14 are preferably constructed by utilizing the apparatus and method illustrated in FIGS. 1, 4 and and described in detail below. The apparatus comprises a table top or surface plate 68 adapted to be supported in a horizontal position by any suitable means such as legs 70. The table-top is formed from magnetizable material and may, if desired, be provided as a permanent magnet for certain installations. However the table top 68 disclosed herein has electric coils 72 embedded therein and spaced substantially throughout its entire length and width, which coils are electrically connected with each other and with an electrical cord 74 which is adapted to be connected with a suitable source of electricity. Thus the table top 68 is constructed in the form of an electromagnet whereby the magnetic field around the table top may be increased or decreased or entirely removed, as desired.

As shown in FIGS. 1 and 6, T-slots 76 and 78 are formed in opposite side edges of the table top 68 immediately above laterally projecting flanges 80 and 82. These flanges are respectively marked with suitable indicia for providing a calibrated scale along each side of the table top.

Standards 84 and 86 are disposed at opposite sides of the table top 68 and extend upwardly therefrom as shown in FIGS. 1 and 6, which standards are respectively mounted on T-slides 88 and 90. The slides extend into the T-slots 76 and 78 respectively so that the standards 84 and 86 are mounted for sliding movement along the opposite side edges of the table top 68. It is to be noted that the standards are positioned so that an edge thereof or a suitable mark provided thereon is adapted to co-operate with .the scales provided on the flanges 80 and 82 for enabling an operator accurately to position the stand ards at any desired location along the opposite side edges of the table top 68. I

A calibrated rod or bar 92 extends between and is fixed to upper end portions of .the standards 84 and 86 at a location spaced well above the upper surface of the table top 68. A slide member 94 is disposed on the rod and is provided with a suitable edge or marking co-operable with the scale markings on the calibrated rod 92 for enabling an operator to position the slide With great pre cision in a predetermined manner. A pointer 96 is fixed on the slide 94 and depends therefrom which pointer may be used for engaging and determining the exact location of blade elements during the construction of the die mem bers.

When constructing a die set in accordance with the pres ent invention, it is contemplated that a full size drawing of one of the die members, preferably the male die member 12, will first be made. The drawing 98 having lines thereon substantially showing the proper position of the die elements 28 is then placed on the table top 68 as shown in FIGS. 1 and 5. The frame structure 22 is then accurately positioned on the drawing 98 whereupon the electromagnetic table 68 is energized for magnetically clamping the frame structure 22 against the table top. This action not only serves to retain the frame structure 22 in the desired position, but the frame structure in turn clamps the drawing 98 in the desired position.

The blade elements 28 are cut and formed in accordance with the shapes and dimensions shown on the drawing 98 whereupon the blade elements are placed directly on the lines on the drawing as shown in FIGS. 1, 4 and 5. The bottom edges 30 of the blade elements 28 are flat and are perpendicular to theside surfaces of the blade elements. It has been found that with the blade elements constructed in this manner, the magnetic field around the table top 68 will serve to hold the blade elements firmly down on the drawing and in any desired upright position to which they may be adjusted by a workman. As previously indicated, the workman will place the blade elements on the lines of the drawing.

Whilethe drawing 98 should be made accurately, it is recognized that there may be inaccuracies in the draw ing as a result of minor drafting errors. Thus after the blade elements 28 have been positioned on the lines of the drawing, the workman will check the position of the various portions of the blade elements 28 by utilizing the pointer 96 on the slide 94 which, of course, can be accurately positioned at any desired location above the table top 68 by adjusting the standards 84 and 86 along the calibrated flanges and 82 and by adjusting the slide 94 transversely of the table top along the calibrated rod or bar 92. As a workman checks the position of the various blade elements 28 with the aid of the pointer 96, he can make any necessary adjustments in the position of the blade elements by sliding the blade elements over the drawing. In other words the drawing is utilized for obtaining a close approximation of the desired position for the blade elements 28 while the measuring means including the pointer 96 and its associated supporting elements and scales may be used for facilitating final and accurate adjustment and positioning of the blade elements.

As shown best in FIGS. 4 and 5, one or more spacing blocks 100 are disposed along and in abutting relationship with each of the blade elements 28. These blocks 100 are preferably formed from a magnetizable material and may serve not only as spacing blocks for the purpose described below, but also for aiding in positioning and supporting the blade elements 28.

The bushings 38 are also placed directly on the drawing 98 and positioned in accordance with appropriate markings on the drawing. The position of the bushings may be checked by the measuring means including the pointer 96 if desired. A plurality of the spring or knockout devices 42 may also be arranged as desired on the drawing. a

After all of the parts have been properly positioned on 'the drawing in the manner described above, the material for the body is provided in liquid form and poured or cast directly onto the drawing and around and within the pattern provided by the blade elements 28.-

If desired the drawing may first be sprayed or otherwise coated witha releasing agent so that it will not adhere to the body 20. The plastic or other suitable material for the body 20 is poured until the desired level is reached, which level is substantially equal to the height of the spacing blocks 100 as shown best in FIG. 5. The liquid material is then allowed to harden, and in certain instances heat may be applied for increasing the rate of hardening. This hardening of the material of the body 20 completes the construction of the die member 12.

In accordance with an important feature of the present invention, the method for constructing the die member 14 is as followsz-After, the die member 12 has been formed and the material of the body 20 has hardened, a coating of a releasing agent is sprayed or otherwise applied to the upper surface of the body 20 and the exposed portions of the blade elements 28. Then the blade elements 54 are cut and shaped so that they correspond to the dimensions, arrangement and configuration of the blade elements 28 whereupon the blade elements 54 are positioned and retained in direct relationship with the blade elements 28. Preferably shim strips 102 are placed between the blade elements 54 and the blade elements 28 as shown in FIG. 5 for providing a predetermined substantially uniform clearance between the blade elements 54 and the blade'elements 28 around the entire pattern. In certain instances, it is contemplated that the blade elements 54 may be positioned directly against the blade elements 28. In any event the blade elements 54 are clamped directly with respect to the blade elements 28 either with or without an intervening shim as shown in FIG. 5 whereby all portions of the blade elements 54 are positioned exactly in accordance with and conformed to the dimensions and configuration of corresponding portions of the blade elements 28. This assures proper coaction between all portions of the blade elements 54 and 28 without undue interference therebetween regardless of any slight errors which may have been made in the arrangement of the blade element 28. It will be appreciated that various clamping devices may be used for securing the blade elements 54 with respect to the blade elements 28, and FIG. 5 shows pivoted and spring biased C-clamps 104 in position for holding the blade elements 54 against the blade elements 28.

As shown in FIG. 5, the blade elements 54 are positioned with their bottom edges resting on the upper surfaces of the spacing blocks 100.. The bushings 52 for the die member 14 are positioned on top of the bushings 38 which have a height identical to that of the spacing blocks 100 whereby the lower faces of the bushings 52 and the edges of the blade elements 54 are disposed substantially in a common plane which substantially corresponds -to the upper surface of the body 20. Guide rods 40 may be inserted through the bushings 38 and 52 in order to assure proper alignment of these bushings. Either-before or after the blade elements 54 and the bushings 52 are positioned in the manner described, the frame structure 46 is disposed on the upper edge of the frame structure 22 and is magnetically secured in the desired position.

When the blade members 54, the bushings 52 and frame 46 have been properly secured in position in the manner described above, the body 20 is coated with a suitable releasing agent and the material for the body member 44 is provided in liquid form and is poured or cast directly onto the coated upper surface of the body 20 and within and without the pattern provided by the blade elements. When sufiicient material has been poured to retain the blade elements 54 in place, the clamping devices 104 may be removed after which the remainder of the body member 44 will be poured. It is contemplated however, that suitable clamping devices, which could remain embedded in the body 44 might be used and "also that the elements '54 may be magnetically held without the aid of' any clamping devices. In any event, after the material of the body 44 has hardened the die member 14 is lifted from the die member 12. It will be noted that when this method is used, the die elements 28 not only serve to support and locate the blade elements 54, but they also serve as core elements for forming the slots 66 in the body member 44. Of course the shims 102 also aid in forming the slots 66, which shims are removed from the slots after the die member 14 has been lifted from the die member 12.

While the preferred embodiment of thepresent invention has been shown and described herein, it is obvious that many details may be changed without departing from the spirit and scope of the appended claims. For example, it

. is contemplated that in certain instances it may be desirable to utilize mechanical clamping means in addition to .or in place of the magnetic table 68 for clamping and retaining the blade members, bushings, frame structures or other elements of the die members. Such clamping means could be secured directly to the table top by a bolt threaded into one of a plurality of apertures formed in table top and closed by suitable threaded plugs when not in use. The sequence in the steps of positioning the various parts of the die members and pouring the various portions of the die body members may also be varied. In certain instances the body members 20 and 44 may be laminated and may incorporate sheets of suitable reinforcing material such as fiber-glass. It is also contemplated that the die member 14 may be built first so that the die elements 54' will be used to locate and support the die elements 28 during completion of the construction of the die member 12. Furthermore in certain instances it is unnecessary to wait for the first poured die body member to be completely hardened before pouring the second body member and in such instances it is contemplated that a divider or separator sheet of suitable material would be placed on top of the first poured body member before beginning to pour the second body member.

The invention is claimed as follows:

1. A method of making a die structure comprising providing a first die member having a body and blade means on said body providing a workpiece processing edge extending in 'a predetermined pattern, then positioning and supporting a workpiece engageable blade element of a second die member in association with and with respect to said blade means, subsequently forming a body of fluid material around said blade element and hardening said second mentioned body, positioning a guide rod for extending between the first and second mentioned bodies before said second mentioned body is formed, placing a bushing on said guide rod, and forming said second mentioned body around said bushing as Well as around said blade element.

2. A method of making a dicstructure comprising pro-' viding a first die member having a body presenting a generally horizontally disposed upwardly facing surface and means on said body and projecting upwardly above said surface and providing a workpiece processing edge arranged in a predetermined pattern and presenting a substantially vertical exposed surface above said horizontal surface and intersecting said edge, then securing a workpiece engageable and processing element of a second die member to said means and substantially directly against said vertical disposed surface of said means and in a position substantially abutting said upwardly facing surface and extending upwardly from said edge, pouring a second body of harden-able fluid material over said upwardly facing surface and around and in contact with said element, and hardening said material and then relatively separating said die members.

' 3. A method, as defined in claim 2, which includes a step of securing a spacing member between said ele- 7 ments prior to the [forming of said second body for providing a predetermined spacing of said elements [from each other.

4.- A method, as defined in claim 2, which comprises the steps of utilizing elongated blade members as said means and said element, and clamping said second element directly with respect to said means.

5. A method, as defined in claim 2, which includes the step of covering said first body prior to the forming of said second body for preventing said second body from adhering to the first body.

References Cited by the Examiner UNITED STATES PATENTS 8 Bates et a1. 76-107 Frost 83652 Mertinz 83652 Berlin et al. 76107 X Lescallette 76-107 Smith 76--107 Linzell et al 76-1-O7 Phillips et a1 76-107 Berlin et al; 76-107 X GRANVILLE Y. CUSTER, J 11., Primary Examiner.

CARL W. TOMLIN, Examiner.

15 J. B. MCGUIRE, D. D. SCHAPER,

Assistant Examiners. 

1. A METHOD OF MAKING A DIE STRUCTURE COMPRISING PROVIDING A FIRST DIE MEMBER HAVING A BODY AND BLADE MEANS ON SAID BODY PROVIDING A WORKPIECE PROCESSING EDGE EXTENDING IN A PREDETERMINED PATTERN, THEN POSITIONING AND SUPPORTING A WORKPIECE ENGAGEABLE BLADE ELEMENT OF A SECOND DIE MEMBER IN ASSOCIATION WITH AND WITH RESPECT TO SAID BLADE MEANS, SUBSEQUENTLY FORMING A BODY OF FLUID MATERIAL AROUND SAID BLADE ELEMENT AND HARDENING SAID SECOND MENTIONED BODY, POSITIONING A GUIDE ROD FOR EXTENDING BETWEEN THE FIRST AND SECOND MENTIONED BODIES BEFORE SAID SECOND MENTIONED BODY IS FORMED, PLACING A BUSHING ON SAID GUIDE ROD, AND FORMING SAID SECOND MENTIONED BODY AROUND SAID BUSHING AS WELL AS AROUND SAID BLADE ELEMENT. 